Close to 100 wounded people, including children, were rushed to hospitals. Among them were several university students who had been travelling in a bus, Hussein said.

A large plume of black smoke rose above the capital, marking one of the deadliest attacks in Mogadishu in recent memory.

There were conflicting reports about the number of casualties. Speaking to Al Jazeera, the adviser to Mogadishu’s mayor said the death toll “is above 90 at the moment”.

“There are many casualties as well so the death toll is expected to rise,” Hodan Ali said, adding that the explosion took place at the Ex-Control junction.

Abdiqadir Abdirahman, director of the Aamin Ambulance service, said 61 people were killed in the attack.

Al Jazeera’s Haru Mutasa said Somali police officers were among the casualties.

“We can expect more injuries and casualties once these numbers are officially tallied,” she said, speaking from Nairobi. “A lot of officials are saying their priority is to try to help those who have been injured, trying to get them to hospitals as quickly as possible and then, of course, count the dead.”

Rescuers carried bodies past the twisted wreckage of a vehicle and a minibus taxi smeared with blood.

Three witnesses told Reuters that a small team of Turkish engineers were present at the time of the blast at the Ex-Control checkpoint, constructing a road from the checkpoint into the city.

A car belonging to the engineers was destroyed instantly in the blast, the witnesses said.

Somali Foreign Minister Ahmed Awad later tweeted that two of the Turkish engineers died in the blast.

Many of the dead were “students with ambition, and hardworking men and women”, he wrote.

Turkey’s foreign ministry confirmed the death of two of its nationals.

‘Scattered dead bodies’

Speaking to reporters at the blast site, Mogadishu Mayor Omar Muhamoud said the government confirmed at least 90 civilians, mostly students, had been injured in the explosion.

“The blast was devastating,” said police officer Ibrahim Mohamed. “I can confirm more than 20 civilians killed, there were many more wounded, but the toll can be higher.”

Sakariye Abdukadir, who was near the area when the car bomb detonated, said the blast “destroyed several of my car windows”.

“All I could see was scattered dead bodies… amid the blast and some of them burned beyond recognition.”

Government authorities have told medical personnel not to disclose figures as they have done in the past, and journalists are forbidden from going to attack sites.

There was no immediate claim of responsibility for the blast.

The attack again raises concerns about the readiness of Somali forces to take over responsibility for the country’s security from an African Union force in the coming months.

Somalia has been riven by conflict since 1991, when clan warlords overthrew former leader Siad Barre, then turned on each other.